8.4 Photosynthesis has a global impact

Summary:

• carbon cycle that occur on a global scale on Earth depend on the metabolism of tiny chloroplasts and mitochondria
• both producers and consumers' cellular respiration returns carbon dioxide to the atmosphere
• other chemical process on the planet doesn't match the output of photosynthesis
• carbon dioxide is the main element of the carbon cycle
• during cellular respiration, most organisms give off carbon dioxide as wastes
• all the organisms on Earth has a very large effect on the amount of carbon dioxide in the atmosphere
• greenhouse effect, carbon dioxide in the atmosphere traps heat from the sun that would otherwise escape from Earth back into space, which keeps the world climate warm enough for living things

Voabulary:

1. carbon cycle - process by which carbon moves from inorganic to organic compounds and back
2. greenhouse effect - process by which atmospheric gases trap heat close to Earth's surface and prevent it from escaping into space

Concept Check:

2. It helps to keep the temperature on earth warm enough for organisms.

8.3 The Calvin cycle makes sugar from carbon dioxide

Summary:

Trip Around the Calvin Cycle

• The starting material of Calvin cycle is regenerated each time the process occurs
• The starting material that gets regenerated is RubP
• Inputs of Calvin cycle: carbon dioxide from the air, ATP and NADPH produced by light reactions
• Output of Calvin cycle: an energy-rich sugar molecule, which is G3P
• G3P is the raw material used by plant cells to make glucose and other organic molecules

Summary of Photosynthesis

• Equation: 6CO2 + 6H2O - - - 6C6H12O6 + 6O2
• Light reacion converts light energy to the chemical energy of ATP and NADPH in the thylakoid membranes
• Calvin cycle uses ATP and NADPH to convert carbon dioxide to sugar in the stroma
• Photosynthesis is the first step in the flow of energy through an ecosystem
• Photosynthesis is the ultimate source of all the food you eat and all the oxygen you breathe

Concept Check:

1. Inputs are carbon dioxide from the air, ATP and NADPH produced by light reactions, outputs are G3Ps, which are rich-sugar molecules.
2. Light reaction. The Calvin cycle.
3. It's called a cycle because the starting material is regenerated each time the process occurs.
4. Sugar, and plant use it to build other organic molecules.

8.2 The light reactions convert light energy to chemical energy

Summary:

• Sunglight is a form of electromagnetic energy, which travels in waves
• Different forms of electromagnetic energy have characteristic wavelengths
• Visible light makes up only a small fraction of the electromagnetic spectrum
• Wavelenghts that are shorter than those of visible light have enough energy to damage organic molecules
• A substance's color is due to pigments
• When light shines on a material that contains pigment it can be absorbed, transmitted, or reflected, which depends on the wavelengths
• Chloroplast convert some absorbed light into chemial energy
• Chloroplast don't absorb green light
• We could observe the different pigments in a green leaf by using paper chromatography
• Within the thylakoid membrane, chlorophyll and other molecules are arranged in photosystems
• Whenever a pigment molecule absorbs light energy, one of the pigment's electrons gains energy
• That electron will falls back to the ground state and transgers the energy to a neighboring molecule immediately
• The energy transfers between molecules and arrives at the reactin center of the photosystem, which includes a primary electron acceptor
• The light reactions involve two phtosystems connected by an electron transport chain
• Respiration food provides the electrons for the electron transport chain of light reaction
• The second photosystem is NADPH producing photosystem
• The light reactions convert light energy to the chemical energy of ATP and NADPH

Vocabulary:

1. wavelength - distance between adjacent waves
2. electromagnetic spectrum - range of types of electromagnetic energy from gamma waves to radio waves
3. pigment - chemical compound that determines a substance's color
4. paper chromatography - laboratory technique used to observe the different pigments in a material
5. photosystem - cluster of chlorophyll and other molecules in a thylakoid
   

Concept Check:

1. A leaf appears green because green light is not absorbed and being reflected.
3. ATP and NADPH
4. It takes place in the thylakoid membrane

8.1 Photosynthesis uses light energy to make food

Summary:
- Photosynthesis takes place in choloroplast
- Choloroplast contians chlorophylls that makes those organelles green

- Leaves are the major sites of photosynthesis in most plants

- Chloroplasts are concentrated in mesophyll's cells of leaves

- Carbon dioxide enters and oxygen exits through the stomata of a leaf
- Veins delivers things throughout the leaf and other parts of the leaf

- The inner membrane of a chloroplast encloses stroma, and stroma are fromed by thylakoids

- The structures of chloroplast organize the complex series of chemical reactions that make up the processes of photosynthesis

- Chemical equation for photosynthesis:6CO2+ 6H2O --- C6H12O6 + 6O2

- Stages of photosynthesis: light reaction & Calvin cycle

- Light reaction convertthe energy in sunlight to chemical energy and store it in NADPH and ATP

- Calvin cycle makes sugar from the atoms in carbon dioxide plus the hydrogen ions and high-energy electrons carried by NADPH

- Calvin cycle doesn't directly need light to begin but light reaction does

Vocabulary:

1) chloroplast - cellular organelle where photosynthesis takes place

2) chlorophylls - chemical compounds that give give chloroplasts green color

3) stroma - thick fluid contained in the inner membrane of a chloroplast

4) thylakoids - disk-shaped sac in the stroma of a chloroplast; site of the light reactions of photosynthesis

5) light reaction - chemical reactions that convert the sun's energy to chemical energy; take place in the membranes of thylakoids in the chloroplast

6) Calvin cycle - cycle in plants that makes sugar from carbon dioxide, H+ ions, and high-energy electrons carried by NADPH

Conecept Check:

1.

2. Reactants: carbon dioxide, water; products: glucose, oxygen

3. The light reaction and the Calvin Cycle. They are related becasue the energy converted by the light reaction were stored in ATP and NADPH, and those two are the two input supplies of the Calvin cycle.